Device for producing an exhaust gas-oil mixture to be supplied to a main burner of a nozzle-free oil-gasifying burner installation



June 30, 1970 HANS KARL LEISTRITZ 3,513,035

DEVICE FOR PRODUCING AN EXHAUST GAS-OIL MIXTURE TO BE SUPPLIED TO A MAIN BURNER OF A NOZZLE-FREE OIL-GASIFYING BURNER INSTALLATION Filed June 14, 1968 INVENTOR HANS KARL LEISTRITZ ATTORNEY United States Patent Ofiice 3,518,035 Patented June 30, 1970 Int. c1. Fzsa 11/44 US. Cl. 431-207 6 Claims ABSTRACT OF THE DISCLOSURE A precombustion chamber having an upstream end portion is formed by a portion of an elongated gas duct, which is formed with air intake openings only in said upstream end portion. Partitioning means partition an oil container from said precombustion'chamber and define a first oil inlet opening between said oil container and said precombustion chamber. Means are provided which define a gas-oil contacting chamber, a gas inlet between said gas-oil contacting chamber and said gas duct downstream of said precombustion chamber, a gas outlet. At least part of the length of said gas duct is free of means adapted to maintain liquid oil in said duct. A flame formed on the surface of the oil at the upstream end of said precombustion chamber will extend into and will be extinguished in the gas duct downstream of said precombustion chamber, and hot exhaust gases from said flame will be enriched with oil vapor from a body of oil in said gas-oil contacting chamber.

An oil-gasifying burner installation which comprises such a device is known from the Austrian patent specification 254,456. In that known installation, the elongated duct has only a top wall and two side walls and is confined below by the surface of the oil. The duct serves to ensure that the flame produced in the precombustion chamber is restricted to a small area of the surface of the oil so that a good vaporization of the oil is effected by a precombustion which involves only a relatively small energy. The duct ensures also a fairly high velocity of flow. This high velocity of flow is required to remove the vapor as quickly as possible from the surface of the oil so that the entire body of oil does not undergo an excessively high temperature rise. As contrasted therewith, a high velocity of flow is not produced in a burner according to the US. Pat. 1,271,680 because the gases can emerge from the precombustion chamber all directions.

It is an object of the invention to provide a device in which the oil in the precombustion chamber can be evaporated with even less energy, involving a lower consumption of oil.

It is also an object of the invention to provide a device in which waste oils which contain water can also be used, even if their water content is close to the limit for water-in-oil emulsions.

In a device of the kind defined first hereinbefore, these objects are accomplished in that the gas duct is free of liquid oil at least in part of its length. The oil-free portion of the gas duct is completely surrounded by a wall. The exhaust gas-oil mixture (which will briefly be referred to as gas hereinafter) which emerges from the oilfree portion of the gas duct is at a much higher temperature than the oil previously emerging from the elongated duct which extends on the surface of the oil throughout its length. In the device according to the invention, there is no evaporation of oil throughout the length of the duct;

such evaporation involves a dissipation of heat from the gas.

The very hot gas emerging from the oil-free portion of the gas duct impinges on a relatively small portion of the surface of the oil in the gas flow chamber which precedes the main burner. In this chamber, there is an increased evaporation at the surface of the oil, which sur face is not contacted by a flame so that there is no formation of carbon black. The temperature rise of the entire body of oil is also reduced in this way.

In a development of the invention, this effect may be increased in that the side walls and the bottom of the precombustion chamber are provided with a heat-insulating layer so that a good thermal separation is effected between the precombustion system, on the one hand, and the oil container and the main burner, on the other hand.

In a development of the invention, the precombustion chamber may have a bottom which is on a higher level than the bottom of the oil container; in this case, at least one oil inlet opening leading into the precombustion chamber may be disposed at the upstream end of the precombustion chamber below the lowest oil surface level to be expected in operation. At least one oil inlet opening is then disposed close to the air intake openings leading into the precombustion chamber, i.e., close to the point where precombustion flame is formed. This has the advantage that the water has been evaporated from the oil which is flowing into the precombustion chamber so that the precombustion chamber is filled with oil which does not contain droplets of water as suspended particles. This result could not be achieved if the oil were permitted to enter the precombustion chamber at points other than the upstream end. Said arrangement of the oil inlet opening avoids a sudden formation of water vapor in the precombustion chamber in such amounts as would extinguish theflame in the precombustion chamber.

A11 illustrative embodiment of the invention will be described hereinafter with reference to the drawing, which shows only the device for producing the exhaust gas-oil mixture whereas the main burner is omitted.

The oil container 1 contains a body of oil 2 and is airtightly covered at the top by the cover 4. A short pipe 6 is mounted on the cover 4, gas-tightly joined to an opening of the cover and closed at the top.

The precombustion chamber 8 is confined by a bottom 10, side walls 12 and 13 and two further side walls 14, respectively dispose before and behind the plane of the drawing. The wall 13 extends upwardly into the short pipe 6 and-is tightly joined to it along both side edges. The bottoni 10 and the walls 1 2, 13 and 14 are insulated by asbestos layers 17.

The walls of the precombustion chamber 8 are tightly closed everywhere except for the following three open- 1ngs:

A tubular screen 11 extends through the cover 4 into the precombustion chamber down to the bottom thereof. A cap 15 is disposed above the tubular screen and is vertically adjustable with the aid of a screw 15 for an adjustment of the air inflow rate.

A connecting pipe 16 extends within the tubular screen through the bottom 10 of the precombustion chamber and forms the oil inlet opening.

A gas outlet opening 18 is disposed between the upper end of the wall 13 and the top cover of the connecting pipe 6. From the opening 18, the gas flows into the gas flow chamber 20, which leads to the main burner.

Air" to support the precombustion enters the tubular screen .11 under the rim of the cap 15. The flame is formed on the surface of the oil at the tubular screen and extends into the precombustion chamber 8 and the gas flow chamber 20 to a smaller or larger extent, de-

3 pending on the rate at which air is supplied through the cap 15. The flame and its hot exhaust gases cause an evaporation of oil. The oil vapor is entrained by the gas stream.

When the level of oil in the precombustion chamber 8 is controlled by a float, not shown, it will be ensured even still more perfectly that the water content is evaporated from the oil before the latter enters the precombustion chamber 8. To this end, the pipe 16 may be extended upwardly almost to the surface level of the oil, or the tube 11 may have an unapertured lower part so that the lowermost holes in the tubular screen are on or slightly below the oil surface level.

It will be understood that this invention is subject to modification in order to adapt it to diflerent uses and conditions.

What is claimed is:

1. A device for producing an exhaust gas-oil mixture to be supplied to the main burner of a nozzle-free oil gasification burner installation comprising means defining an elongated gas duct having an upstream portion at one end and its other end leading to a main burner,

a pre-combustion chamber within said gas duct at the upstream portion thereof,

an oil container in the upstream portion of said gas duct and extending downstream of said pre-combustion chamber,

the portion of said oil container downstream of said precombustion chamber opening to the gas duct to define a gas-oil contacting chamber within the gas duct,

an air inlet in the upstream end of said gas duct to said precombustion chamber and an oil inlet between said oil container and said pro-combustion chamber so that a flame may be formed on the surface of the oil in said pre-combustion chamber,

means in said gas duct for defining a gas inlet to said gas-oil contacting chamber from said gas duct downstream of said pre-combustion chamber and a gas outlet from said pre-combustion chamber,

the surface of the oil in said oil container terminating short of said gas inlet and gas outlet so that the portion of the gas duct between said gas inlet and gas outlet is non-continguous to the oil surface whereby the flame will extend into and Will be extinguished in the gas duct downstream of said pre-combustion chamber and hot exhaust gases from said flame will be enriched with oil vapor from a body of oil in said gas-oil contacting chamber.

2. A device as set forth in claim 1 in which, said duct comprises a top member defining said pre-combustion chamber,

said duct further comprises a U-shaped portion which extends upwardly from said top member and then downwardly to said gas inlet, and

said U-shaped portion is free of means adapted to maintain liquid oil in said U-shaped portion.

3. A device as set forth in claim 1 in which said precombustion chamber 'has an upstream end formed with said oil inlet, which is disposed below the lowest oil level to be expected in said pre-combustion chamber during the operation of said device.

4. A device as set forth in claim 1 in which said container has a bottom and said pre-combustion chamber has a bottom which is spaced above the bottom of said container.

5. A device as set forth in claim 1 in which said precombustion chamber has a side wall and bottom and said side wall and bottom are covered by a heat-insulating layer.

6. A device as set forth in claim '5 in which said heatinsulating layer comprises asbestos.

References Cited FOREIGN PATENTS 556,852 5/1957 Belgium. EDWARD G. FAVORS, Primary Examiner US. Cl. X.R. 48-107 

